1. Field of the Invention
Conventional methods of dispensing chlorine into swimming pools is accomplished by transporting a small cylinder of liquid chlorine, and chlorine gas is dispensed from the cylinder into the pool water. The small cylinder is filled by transferring liquid chlorine from a larger supply cylinder. This is accomplished by cooling the small cylinder in a freezer chest and connecting the small cylinder to the supply cylinder through a transfer valve manifold. Due to the lower vapor pressure of the chlorine in the small cylinder, liquid chlorine flows from the supply cylinder to the small cylinder. When the small cylinder is full, the valves on the small cylinder, the supply cylinder, and the transfer valve manifold are closed trapping some liquid chlorine in the passage ways of the transfer valve manifold and the connector tube to the small cylinder. To prevent this chlorine from being discharged into the atmosphere when the small cylinder is disconnected, a bleed valve is opened on the transfer valve manifold and this chlorine is discharged into a caustic scrubber solution.
This method requires the preparation and disposal of spent caustic solution. A caustic storage tank, a barometric loop, and a pump to circulate the caustic solution through a venturi to suck the chlorine from the transfer valve manifold.
2. Description of the Related Art
The prior art describes many valve arrangements for transferring of liquified gases from one container to another without the escape of any significant amount of the gases being transferred. A pertinent reference is U.S. Pat. No. 1,000,945 issued to William Ray in August 1911, describing an arrangement of two valves connected as a twin valve coupling "whereby when the valves are closed the intervening space becomes nil" U.S. Pat. No. 8,2,372,820 issued to Gardes in April 1945, describes a conduit connection for a fluid pressure control adapted to provide quickly detachable connections in conduits leading from one of a fluid pressure control mechanism to another. U.S. Pat. No. 2,502,630 issued to Morrison in July 1946, describes a disconnectable coupling having a manually closable valve in each section.